Spurs were 3-0 up at half-time thanks to a Heung-min Son opener and then two goals from Harry Kane as they completely outclassed West Ham.
The second half was a different story, though, as the Hammers pushed and eventually made the breakthrough in the 82nd minute thanks to a Fabian Balbuena header.
A Davinson Sanchez own goal in the 85th minute really spiced things up before Manuel Lanzini produced a stunning strike with the last kick of the game to grab a point.
Mourinho put a brave face on the obvious disappointment of the situation, dismissing the situation as just something that happens in football.
‘Football [happened] and of course I have to analyse the second half and I have to do it internally,’ Mourinho told Sky Sports. ‘For you I prefer to say that football happened and I prefer to praise West Ham’s belief
‘It’s not easy to be losing 3-0 and to be dominated, we had the game under control, it’s not easy to keep the belief.
‘I knew they are a completely different team to last season so I give them credit.
‘But of course to concede three goals and to lose an advantage of three goals is a big punishment and eventually deserved.
‘I will find things and I found already things already just by analysing the game from the touchline, but some of the things are completely out of context.
‘That’s football and we were punished.’
On another weekend of thrilling games in the Premier League, that has also seen Chelsea and Southampton draw 3-3 and Everton draw 2-2 with Liverpool, Mourinho would not speculate on what is producing the huge amount of goals.
‘This was a game that was in the pocket and we lost, I have to focus on that,’ he said.
The Welshman brilliantly created a chance to put the game to bed for Tottenham late on but then made a mess of the finish when in on goal.
Bale was fit to start the game but Mourinho insists it was the right call to leave him on the bench.
‘The decision not to start him was a good one,’ the Portuguese told a press conference. ‘It showed he doesn’t have a beautiful chair waiting for him in the team and it’s there for him when he’s ready.
‘Everybody has to fight. He’s come into the group well, everybody likes him and he likes what he’s found here. It’s a pity he couldn’t score that fourth goal that would have been crucial.’